public class AppTest 
{
  public static void main(String[] args) throws Exception
  {
    IVideoUserService guest = new GuestVideoUserService();
    {
      guest.definition();
      guest.advertisement();
    }
    IVideoUserService ordinary = new OrdinaryVideoUserService();
    {
      ordinary.definition();
      ordinary.advertisement();
    }
    IVideoUserService vip = new VipVideoUserService();
    {
      vip.definition();
      vip.advertisement();
    }
  }
}
